The present invention relates to a connecting tube structure, comprising a connecting tube with both ends respectively joined to a faucet and a shower head wherein the connecting tube has a stop plate at one end to mount to a grooved seat of a rotary-sealing device and a cavity at the other end for the accommodation of one check valve with a movable plug supported by a spring to shut off water discharge and prevent the return of dirty water. The rotary water-sealing device, having watertight O-rings adapted to the upper section and a V-shaped side wall extending at the lower section, is sealed to the bottom and internal surface of the shower head and enclosed by a screw nut secured to the shower head, providing high-and-lower pressure water-sealing benefit as well as rotation in 360 degrees thereby.
Please refer to FIGS. 1, 2. A conventional connecting tube structure includes a water-discharge body 1 having an external-threaded portion 11 extending at the bottom, and a T-shaped head 21 disposed at the end edge thereon to combine with a connecting tube 2 thereby. The T-shaped head 21 has a middle section defined by an annular groove 22 to which a washer 23 is accommodated, and a screw nut 24 is applied to enclose the T-shaped head 21 at the outer side of the connecting tube 2. The T-shaped head 21 is placed at one bottom edge 111 of the external-threaded portion 11 of the water-discharge body 1, and the screw nut 24 with an O-ring 12 is utilized to secure to the external-threaded portion 11 thereof. Therefore, the T-shaped head 21 is squeezed by the bottom edge 111 of the external-threaded portion 11 and enclosed by the screw nut 24 secured to the external threaded portion 11 thereof.
However, there are some drawbacks to such conventional connecting tube structure. Most of all, when the connecting tube 2 is combined with the water-discharge body 1, the T-shaped head 21 attached at the end edge of the connecting tube 2 is fixedly secured to the water-discharge body 1 as one unit. As a result, the water-discharge body 1 (e.g. a shower head) twisted and turned in application will wind up the connecting tube 2 therewith accordingly. Finally, the connecting tube 2 can get tied up and hinder the discharge of water supply. Besides, the connecting tube 2 twisted and turned in the long run can easily get worn off and become reduced in its durability thereby, which not only waste resources and money but can increase the amount of garbage. Furthermore, the T-shaped head 21 and the screw nut 24 are bound by one-way force, which can easily result in the disadvantage of water leakage. The water-discharge body 1 cannot properly shut off the water discharge via external or internal parts thereof, and even the connecting tube 2 fails to provide water-sealing function. Thus, water leakage and the return of dirty water happen over and over again, which can cause the waste of water resource as well as make dirty the places such as bathrooms or kitchens thereof.